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Related papers: Modelling a $2.5 \, M_{\odot}$ Compact Star with Q…

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Neutron stars (NSs) are excellent natural laboratories to constrain gravity on strong field regime and nuclear matter in extreme conditions. Motivated by the recent discovery of a compact object with $2.59^{+0.08}_{-0.09} M_\odot$ in the…

High Energy Astrophysical Phenomena · Physics 2020-12-07 Rafael C. Nunes , Jaziel G. Coelho , José C. N. de Araujo

The results of the investigation of the core-envelope model presented in Negi et al. \cite{Ref1} have been discussed in view of the reference \cite{Ref2} . It is seen that there are significant changes in the results to be addressed. In…

General Relativity and Quantum Cosmology · Physics 2021-06-04 P S Negi

We investigate non-radial oscillations of hadronic, hybrid and pure self-bound strange quark stars with maximum masses above the mass of the recently observed massive pulsars PSR J1614-2230 and PSR J0348-0432 with $M \approx 2 M_{\odot}$.…

High Energy Astrophysical Phenomena · Physics 2017-09-01 C. V. Flores , G. Lugones

The transition to quark matter can take place in neutron stars. The structure of a hybrid star, containing a core made of quark matter is discussed. The maximum mass of the non-rotating hybrid star turns out to be 1.6 M_s. Possible…

Astrophysics · Physics 2009-10-31 Alessandro Drago

Recent constraints on neutron star mass and radius have advanced our understanding of the equation of state (EOS) of cold dense matter. Some of them have been obtained by modeling the pulses of three millisecond X-ray pulsars observed by…

The special point is a feature unique to models of hybrid neutron stars. It represents a location on their mass--radius sequences that is insensitive to the phase transition density. We consider hybrid neutron stars with a core of…

Nuclear Theory · Physics 2022-04-05 Mateusz Cierniak , David Blaschke

The observation of gravitational waves from an asymmetric binary opens the possibility for heavy neutron stars, but these pose challenges to models of the neutron star equation of state. We construct heavy neutron stars by introducing…

High Energy Astrophysical Phenomena · Physics 2021-01-04 Hung Tan , Jacquelyn Noronha-Hostler , Nico Yunes

Gravitational-wave observation together with a large number of electromagnetic observations shows that the source of the latest gravitational-wave event, GW170817, detected primarily by advanced LIGO, is the merger of a binary neutron star.…

High Energy Astrophysical Phenomena · Physics 2017-12-27 Masaru Shibata , Sho Fujibayashi , Kenta Hotokezaka , Kenta Kiuchi , Koutarou Kyutoku , Yuichiro Sekiguchi , Masaomi Tanaka

It is currently unknown how matter behaves at the extreme densities found within the cores of neutron stars. Measurements of the neutron star equation of state probe nuclear physics that is otherwise inaccessible in a laboratory setting.…

High Energy Astrophysical Phenomena · Physics 2026-03-03 Kris Walker , Rory Smith , Eric Thrane , Daniel J. Reardon

In this work, under the hypothesis that quark matter may not be strange (Holdom et al. 2018), we adopt a modification of the coupling constant of the four-quark scalar interaction $G\rightarrow G_1+G_2\langle\bar{\psi}\psi\rangle$ in the…

Nuclear Theory · Physics 2025-02-21 Cheng-Ming Li , He-Rui Zheng , Shu-Yu Zuo , Ya-Peng Zhao , Fei Wang , Yong-Feng Huang

It is well known that the equation of state (EoS) of compact objects like neutron and quark stars is not determined despite there are several sophisticated models to describe it. From the electromagnetic observations, summarized in…

Four neutron star radius measurements have already been obtained by modeling the X-ray pulses of rotation-powered millisecond pulsars observed by the Neutron Star Interior Composition ExploreR (NICER). We report here the radius measurement…

While model-independent limits are always interesting, a limit on neutron star radius as a function of mass attains special interest in light of recent interpretations of the periodic as well as quasi-periodic oscillations (QPOs) in…

Astrophysics · Physics 2009-10-31 Norman K. Glendenning

We construct the equation of state for high density neutron star matter at zero temperature using the two-flavor Nambu--Jona-Lasinio (NJL) model as an effective theory of QCD. We build nuclear matter, quark matter, and the mixed phases from…

Nuclear Theory · Physics 2020-05-27 Takehiro Tanimoto , Wolfgang Bentz , Ian C. Cloët

To investigate the missing compact star of Supernova 1987A, we analyzed both the cooling and the heating processes of a possible compact star based on the upper limit of observational X-ray luminosity. From the cooling process we found that…

High Energy Astrophysical Phenomena · Physics 2015-06-03 X. W. Liu , J. D. Liang , R. X. Xu , J. L. Han , G. J. Qiao

Recent gravitational-wave (GW) observations offer a unique opportunity to probe the fundamental nature of compact objects. A growing body of research has focused on exploring the role of dark matter (DM) through the concept of DM-admixed…

General Relativity and Quantum Cosmology · Physics 2026-03-18 Rafael M. Santos , Rafael C. Nunes , Jaziel G. Coelho , Jose C. N. de Araujo

The quark gluon plasma (QGP) at zero temperature and high baryon number is a system that may be present inside compact stars. It is quite possible that this cold QGP shares some relevant features with the hot QGP observed in heavy ion…

Solar and Stellar Astrophysics · Physics 2015-03-20 B. Franzon , D. A. Fogaça , F. S. Navarra , J. E. Horvath

The existence of neutron stars with masses of $\sim 2\,M_{\odot}$ requires a stiff equation of state at high densities. On the other hand, the necessary appearance also at high densities of new degrees of freedom, such as hyperons and…

Nuclear Theory · Physics 2014-03-31 Alessandro Drago , Andrea Lavagno , Giuseppe Pagliara

The first detection of gravitational waves from the binary neutron star merger event GW170817 has started to provide important new constraints on the nuclear equation of state at high density. The tidal deformability bound of GW170817…

High Energy Astrophysical Phenomena · Physics 2019-05-29 Rana Nandi , Prasanta Char , Subrata Pal

We perform an O(alpha_s^2) perturbative calculation of the equation of state of cold but dense QCD matter with two massless and one massive quark flavor, finding that perturbation theory converges reasonably well for quark chemical…

High Energy Physics - Phenomenology · Physics 2010-06-22 Aleksi Kurkela , Paul Romatschke , Aleksi Vuorinen